In his lecture, Revkin said that after covering global warming for almost 20 years, he is convinced that there will never be a time when he can write a story that states clearly that global warming "happened today."

"It is never going to be the kind of story that will give you the level of certainty that everyone seems to crave," he said. "We are assaulted with complexity and uncertainty. Somehow, we need to convey that in all that information, with those question marks, there is a trajectory to knowledge."

American society is uneasy with the equivocal answers that often are the best environmental scientists can provide, said Revkin. Newspapers are uncomfortable with "murk," and politicians and Congress "hate it," he said.

Yet, despite the lack of crystal clarity, "you can still make decisions. Uncertainties don’t let you off the hook," he said, even though some people in politics have used the uncertainties for that purpose.

Unfortunately for, um, everybody, it seems to me that the American public is growing less, not more, tolerant of uncertainty and ambiguity. This is partly a reaction to troubling and confusing times, I suppose, but it’s not helped by a ruling political party that traffics almost exclusively in slogans and nostrums.